curate.pde

void setup() {
  size(500, 500, P3D);
  blendMode(ADD);
  noFill();
  strokeWeight(2);
  frameRate(25);
}

void draw() {
  background(0);
  
  translate(width * 0.6, height / 2);
  rotateY(PI * -0.3);
  
  final int DIVISIONS = 101;
  final float RAD = 150;
  
  final float ANGLE = -(frameCount % 20) * 2 * PI * 0.05;
      
  for (int i = 1; i != DIVISIONS - 1; ++i) {
    pushMatrix();
        
    final float Z = ((i * RAD * 2) / (DIVISIONS - 1)) - RAD;
    final float R = sqrt((RAD * RAD) - (Z * Z));
    
    final float ANGLE_OFFSET = ANGLE + cos(Z / RAD) * 2 * PI;
    
    translate(0, 0, Z);
    stroke(255, 255, 255, 32);
    circle(0, 0, R);

    curate(RAD, R, ANGLE_OFFSET);
    
    translate(sin(ANGLE_OFFSET) * R, cos(ANGLE_OFFSET) * R, 0);
    
    sphere(0.5);
    
    popMatrix();
  }
  
  saveFrame("###-curate.png");
}

void circle(float x, float y, float rad) {
  ellipse(x, y, rad * 2, rad * 2);
}

void curate(float A, float B, float ANGLE) {
  beginShape();
  for (float j = ANGLE; j < 50; j += 0.1) {
    final float X_ = (A * j) - (B * sin(j));
    final float Y_ = A - (B * cos(j));
    vertex(-X_ + ANGLE * A, A - Y_);
  }
  endShape();
}